Governing device



June 21,1927a y 1,633,180

T. JACKSON GOVERNLNG DEVICE Filed Aug.. 24, 1923 his AHovneg PatentedJune 21., 1927.

UNITED slriiri-:s

.PATENT oFFicE- THOMAS JACKSON, on LONDON,` ENGLAND, Assieivon rroGLENDORA Bassin' RAMSAY,

' on FoLKEsroNE, ENGLAND.

GOVERNING DEVICE.

Application filed August 24, 1923, Serial No. 659,077, and in GreatBritain August 31, 1922.

lever through two oppositely disposed yield@V ing resistan'ces, alciiurcated pivotcd lever having two abiitmentsv saidfbiturcated leverbeing adaptedY to be angularly displaced when the lever carrying themass contacts with either oi" the abutments, a valve device mechanicallyassociated with and operable by the bifurcated lever adapted to permit`passage ot' motive fluid under pressure' when the biturcated leverisangularly displaced, a fluid pressure operated control device connecteddirectly or indirectly to the delivery irom the valve device saidcontrol device acting against Van increasing yielding resistance andbeing adapted to return toits initial position on interruption ot thesupply of tluid pressure, connecting means between the control deviceandy that which directly controls the speed of that which is to becontrolled and a source ot motive fluid.

Referring. to the drawings, which form part ot this speciticatiom-Figure l is a front'el-evation of a governing device constructed inaccordance with thisinvention. V

Figure 2 is a fragmentary plan view of Fig. l. v v Fig. 3 isl anenlarged section through the valve device operated by the momentum otthe reciprocating mass tor governing.r

Figure '4 is an enlarged section of one form of the valve deviceassociated with the fluid pressure operated control cylinder.

The device illustrated in the drawings is arranged to employ compressedair or steam under unvarying pressure as motive fluid, the pivoted levera, which for constructional purposes is bifurcated, is adapted to` bereciprocated by the rod connected to a moving part ofV thatv which is"to-abe' controlled,

a secondpivoted lever c carrying' a mass l beingmechanically associatedwith the leverY t by means ot two adjustable springs c e or the like, sothat when the lever a is oscillated it in turn oscillates the lever c.

l It will be seen that owing tothe yielding nature ot the connectionbetween the levers i and c when t-he lever a is oscillated at a certainspeed the leverV c will substantially follow its oscillations but whenthe "speed oit the lever a is increased beyond a certain speed the leverc will havea greatery amplitude of motion due to the inertia fof themass CZ, the critical speed being entirely dependent upon the strengthot the springs e e or the like employed or the position of the mass Z onthe lever c.

The lever c duringr its oscillations 0p- 'erates between stops y vand gmounted on a pivoted biturcated lever L, the distance be'- tween thestops fand g when adj-usted for a specific speed being'suiiicient topermit ot the normal oscillation at that speed of* the lever c withoutcontacty therewith, so V that while the oscillation of the lever c isnormal no displacement of the lever-7L takes place; when however, theoscillation of the lever c becomes abnormal due to increase ot speedabove that predetermined, the stops f and g on lever It are contacted bythe lever c and the lever It is langularly displaced.

The lever L is mounted on' the partl of vthe stem z' which protrudesthrough the cover ot the valve device le which includes a valve seatrZ,a-ball valve Land ball engagingmember a which is carried and operatedbythe part of the stem le' within the device v.

The ball engaging member m. as illustra-ted is provided with four armscachot which can be employed toV operate the' valve m l as required. i

When the lever h is in mid position one of the arms ofvv the ballengaging member; a is also in midposition withA the result that the ballvalve m engages lwith'V its seat Z thus preventing passage of vmotiveiuid lthrough the device c, but` when the lever i; is displaced `fromthe mid posi-tion one or other y of the projections nfof the member nwill engage with. the ball manddisplace it from its seat Zf thus.premitting motive fluid ,toy ilow through the' devicek..

The exi-t connection of the device 7c is connected to a power controlcylinder 0 containing a piston 20 so that when the motive fluid atconstant pressure passes through the device is the piston p is displacedagainst an increasing yielding resistance such as the spring p.

To control the distance through which the piston 20 is displaced by themotive fluid a power operated valve acting against an adjustableyielding resistance is inserted in the operative end of the cylinder 0and is adapted to allow any excess vbeyond a predetermined pressure inthe cylinder 0 to escape.

As illustrated the power operated valve comprises a plunger g hay/'ingportways r therein said portways fr registering with portways s in thebody t during operation of the device, a springu and finger operableadjusting means o being provided to introduce the requisite yielding`resistance.

in operation motive fluid is supplied to the tube at the extreme righthandv side of Figures l and 1i, the pressure of' this motive fluid isalways the same. lf the spring u were not in placethen the piston Qwould pass to the extreme left hand end of its travel. The presence ofthe spring u however prevents this and the spring u is so adjusted thatwhen the motive fluid is applied the piston g moves to th-e leftonlysuch amount as partially will cut off the passage of fluid throughthe portways 1 and s a small escape of motive fluid always freely takingplace.

When the pressure of the motive fluid has been settled for any givenplant then the spring u is adjusted by the finger operable adjustingmeans o so that the portway r slightly overlaps the portway s when themotive fluid exerts pressure on the piston Q. After the spring u hasbeen so adjusted' the pressure of the motive fluid must not be varied.

To ensure that the piston y shall move smartly as soon the motive fluidis admitted, the axial portway which establishes connection between thetransverse portway r and the operative endof the piston g is ofcomparatively small diameter'. In a piston one inch in diameter, thediameter of the axial portway may be one sixteenth of one inch in whichcase the area of the axial portway is only one two hundred and fiftysixth part of the area of the piston Q.

`When motive fluid is admitted under working conditions the piston q.moves to the left until the force exerted by compressing the spring u isequal tothe force exerted by the motive fluid on the end of the pistong; the piston p is also raised bythe motive fluid until the forceexerted by compressing the spring 20 is equal to the force exerted bythe motive fluid on the piston p.

The force available for operating the piston p can be adjusted byvarying the amount of leakage which is permitted to take place throughthe portways 1 and s and thus the travel of the piston j? on operationcan be controlled within wide limits by adjusting the spring u. n

rlhe arrangement outlined above is Vdouble-acting in operation inasmuchas if the velocity of the oscillations of the lever a in eitherdirection is in excess of that predetermined by adjusting the spring c.e displacement of the lever L causes movement of the piston p within thepower cylinder 0.

With such arrangements it is obvious that if the rodeo of the piston pis connected to the control of that which is to be controlled when anyexcess of speed beyond that predetermined talcs place due to disturbanceof load Jfactor automatic control instantly ensues and all racing isprevented.

ln some cases when an abnormal increase of speed takes place or thatwhich is to be controlled for some reason is temporarily unresponsive tonormal governing action a trip device may be provided adapted to preventreturn movement 'of the piston p after displacement of predeterminedamount.

In Fig. l the upper part of the rod L0 is provided with a screw threadwith which a collar fr is operatively engaged a pivoted detent y beingprovided to engage with the collar ai and maintain it in position if thetravel of the rod w is sufhciently excessive. To enable the collar m andthe detent y to be disengaged a pivoted lever z is provided.

l claim:

l. An improved governing device having in combination a pivoted levercontinuously oscillated by theV apparatus the speed of which is to becontrolled, a pivoted lever rigidly carrying a mass adapted to beoscillated by the first named lever through two oppositely disposedyielding resistances, a bifurcated pivoted lever having two abutmentssaid bifurcated lever being adapted to be angularly displaced when thelever carrying the mass contacts with either of' the abutments, a sourceof motive fluid under constant pressure, a valve device mechanicallyassociated with and operable by th-e bifurcated lever adapted to permitpassage of motive fluid under pressure when the bifurcated lever isangularly displaced, a fluid pressure operated control device connectedto the delivery from the valve device said control deviceacting againstan increasing yieldingl resistance and returning to its initialposit-ion on interruption of the supply of fluid pressure.

2. ln an improved governing device as claimed in claim l the arrangementof a fluid pressure operated valve device comprising a cylinder, apiston in said cylinder, a spring for maintaining the piston in positionagainst lthe fluid pressure, a transverse portway in said piston, aportway for cony Leeaiso ducting motive fluid under pressure to saidtransverse portvvay from said cylinder, ports in said cylinder solocated that communication can be effected between said ports and thetransverse portway in said piston to allow motive fluid to escape, anescape branch in the cylinder communicating Withsaid ports, a branch foradmitting motive fluid under pressure into said cylinder and a branchfor conducting motive fluid to a 10 fluid pressure operated controldevice.

In testimony whereof I have signed my name to this specilication.

` THOMAS JACKSON.

